JPH0493237A - Inorganic formed board - Google Patents

Abstract

PURPOSE:To obtain the predetermined shaped projected and recessed pattern and, at the same time, prevent the waterproofing and moisture barrier properties of the board concerned from lowering by a method wherein the densities of the front and rear layers and of core layer of the board concerned are respectively specified and embossing is applied to its front and/or rear surfaces. CONSTITUTION:In inorganic formed board, which is mainly made of woody material such as wood segment board or the like and self-curing inorganic material and on one side or both sides of which embossing is applied, the density of its front and rear layers is set to be 1.0-1.2. If said density is below 1.0, the front and rear sides become too coarse to obtain clear embossing pattern and the waterproofing and moisture barrier properties of a product are also lowered. If said density is 1.2 or more, the weight of the product is too large to handle. The density of core layer is set to be 0.8-1.0. If said density of the core layer is below 0.8, the strength of the core layer and the waterproofing and moisture barrier properties of the product lower. If said density of the core layer is 1.0 or more, the cushioning properties of the core layer lowers and clear embossing pattern is not obtained by the pressing with an retainer plate and a lower retainer plate and, in addition, the product becomes too heavy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an inorganic molded plate that is embossed on both or one side.

[Conventional technology]

Conventionally, as this type of inorganic molded board, a wood chip cement board with unevenness formed on the front and back surfaces has been provided by making the wood chips used for the front and back layers larger than the wood chips used for the core layer (Japanese Patent Application Laid-Open No. 1989-1999) -133511).

[Problem to be solved by the invention]

However, with the above conventional configuration, the uneven pattern on the front and back surfaces depends on the shape of the wood piece, and not only is it impossible to obtain an uneven pattern with a predetermined shape, but the front and back surfaces become rough, reducing the waterproof and moisture-proof properties of the product. do.

[Means to solve the problem]

The present invention provides 1 means for solving the above-mentioned conventional problems.
It consists of a front and back layer and a core layer, and the density of the front and back layers is 1.0 to 1.
．． 2, the density of the core layer is O08 to 1.0,
The present invention provides an inorganic molded plate whose front and/or back surfaces are embossed.

The present invention will be explained in detail below.

The inorganic molded board of the present invention is mainly composed of a wood material and a self-hardening inorganic material, and the wood material includes wood chips, wood flour, wood fiber bundles, bulbs, wood fibers, etc. Hard inorganic materials include cements such as Portland cement, blast furnace cement, silica cement, fly ash cement, and alumina cement, and silica sand and silica powder in addition to the above cements.

Examples include mixtures of silicic acid-containing substances such as silica hume and shirasu balloons, gypsum, and magnesium carbonate.Cement and cement-silicic acid-containing substance mixtures harden by a calcium silicate reaction in the presence of water, and gypsum hardens in the presence of water. Magnesium carbonate hardens by crystal transition. Further, hardening accelerators such as magnesium chloride, magnesium sulfate, calcium chloride, calcium sulfate, sodium aluminate, potassium aluminate, aluminum sulfate, water glass, and mineral powders such as bentonite and pearlite may be added to the above composition.

[Top and back layers] The front and back layers of the inorganic molded plate of the present invention have a density of 1.0 to 1.2, preferably 1.05 to 1.2. The density is 1.0
In the following cases, the front and back surfaces will become rough and clear embossing will not be obtained, and the waterproof and moisture-proof properties of the product will also decrease. On the other hand, if the density is 1.2 or more, the weight of the product becomes large and handling becomes difficult.

The density of the front and back layers is adjusted depending on the size of the wood material used. The density of the wood material that provides the front and back layers is 1.0 to 1.2. The bulk specific gravity of the wood material is usually 0.06 to 0.10 g/cd. Here, the bulk specific gravity is determined by filling a graduated cylinder with an inner diameter of 81 mm and a volume of 2000 m1 with 2000 liters of bone dry wood material, measuring the total weight, and subtracting the weight of the graduated cylinder from the total weight. Determine the weight, place a disc that fits the inside diameter of the graduated cylinder on top of the filled wood material, place a weight on the disc, and apply a weight of 1 kg to the wood material. It is determined by measuring the volume and dividing the weight (g) of the wood material by the volume (ci).

The above wood materials may be a mixture of two or more types, but even in the case of a mixture, the bulk specific gravity should be within the above range.

Desirable raw material compositions for producing the front and back layers are shown below.

Cement: 30-60% by weight silicic acid-containing substance: 3o-60 Perlite: 10-15 Wood chips and/or wood flour: 10-25 The above-mentioned wood chips are usually made of 10 pieces of steel with an average mesh size of 4.5 m and a thickness of 1- The following are desirable;
The wood flour used has a particle size of 5 to 100 mesh, preferably 10 to 30 mesh.

Although wood chips have a stronger reinforcing effect than wood flour, the density of the front and back layers obtained using only wood chips is slightly lower.

On the other hand, if only wood flour is used, the strength of the obtained front and back layers is slightly reduced. Therefore, it is preferable to use wood chips and wood flour together, and in that case, the mixing weight ratio of wood chips and wood flour is 80,820 to 2.
0: Approximately 80.

The silicic acid-containing substance causes smooth and complete hardening of the front and back layers through a calcium silicate reaction with cement, and the resulting product has good dimensional stability.

Pearlite reduces the weight and improves the dimensional stability of the inorganic molded plates produced, so it is a desirable but not essential component for the present invention; If this happens, the strength of the obtained inorganic molded plate will decrease and the front and back surfaces will become rough.

If the amount of wood chips and/or wood flour is less than 5% by weight, the strength of the front and back layers will not be sufficient, and if it is more than 25% by weight, the flame retardance will decrease.

[Core Layer] The core layer of the inorganic molded plate of the present invention has a density of 0.8 to 1.0, preferably 0.8 to 0.95. The density is 0.8
In the following cases, the strength of the core layer will decrease, and the waterproof and moisture-proof properties of the product will also decrease. On the other hand, if the density is 1.0 or more, the cushioning properties of the core layer will deteriorate, clear embossing will not be obtained, and the weight of the product will also increase.

The density of the core layer, like the front and back layers, is controlled by the size of the wood material used. The bulk specific gravity of the wood material that provides the core layer with a density of 0.8 to 1°0 is usually 0.03 to 0.06 g/a.
It is d. The above wood materials may be a mixture of two or more types, but even in the case of a mixture, the bulk specific gravity should be within the above range. In the core layer, plastic, plastic foam, or expandable plastic beads may be added to further adjust the density.

Desirable wood materials for use in the core layer of the present invention are wood fiber bundles made bulky by branching and/or curving and/or bending. The diameter of the main trunk of the wood fiber bundle is preferably about 0°1 to 2.0 cm, the actual length of the main trunk is about 2 to 35 cm, more preferably 10 to 30 m++, and the bulk specific gravity is about 0.03 cm. ~0.05 g/ci (range L).

To produce the wood fiber bundle, the wood is immersed in a chemical solution such as caustic soda, sodium sulfite, or calcium sulfite, heated with steam, or combined with the above-mentioned immersion in the chemical solution and steam heating. The lignin, hemicellulose, resin, etc. that act as a binder for the wood single fibers contained therein are swollen without being completely dissolved, and the above-mentioned binder is left and N-fibrillated. The fibers have a larger diameter than pulp fibers that are defibrated after almost completely removing lignin among the binders. Defibration is carried out using, for example, a grinding disc, and the degree of defibration is adjusted by adjusting the disc gap of the grinding disc.

The above-mentioned wood fiber bundles are branched and/or curved and/or bent, so the excluded volume is large, thus giving a bulky and low-density core layer, but the mutual ends are strong, so the density is low. However, a core layer with high strength can be obtained.

A desirable raw material composition for producing the core layer is shown below.

Cement 30-60% by weight Silicic acid containing material 30-60 #Pearlite
O~15 The above wood fiber bundle 5~25 Expandable plastic beads 0.5~5 What are the expandable thermoplastic beads used in the above invention? Impregnated with a volatile blowing agent such as propane, butane, pentane, or petroleum ether These beads are made of thermoplastic plastic such as polyethylene, polypropylene, or polystyrene.

[Manufacturing Method] As the method for manufacturing the inorganic molded plate of the present invention, it is desirable to adopt a dry manufacturing method that allows easy process continuity and simple equipment. In step 1 of the dry manufacturing method, the raw material mixture for the front and back layers (referred to as mixture A) is spread on the lower template in a mat shape, and then the raw material mixture for the core layer (referred to as mixture B) is spread on top of it. The above-mentioned mixture A is then sprinkled on top of it in a mat shape. At this time, mixture A and mixture B are each mixed with 30 to 30% water for the curing reaction.
Add 45% by weight. When the wood fiber bundles made bulky by branching and/or curving and/or bending are used as the wood material of mixture B, mixture B
This makes it easier to loosen and spread evenly over the lower template.

In the continuous manufacturing method, a large number of the lower templates are placed on a belt conveyor. The raw material mixture spread on the lower mold plate is slightly pressed by a roll or the like if desired, and then an upper mold plate is placed on the upper surface of the mat, and in step 2, it is pressed and precured in the presence of moisture to form the desired shape. molded into a shape. The pressing conditions are usually a pressing pressure of 10 to 20 g/cd,
It is carried out at a temperature of 60 to 80°C for about 20 to 30 hours,
Heating is usually done with steam. Pressing is performed by sandwiching the mat between two upper and lower templates, but in order to embossing the front and/or back sides, a predetermined uneven pattern is applied to the upper and/or lower template surfaces. Set it up.

The precured material obtained by the press precuring in step 2 is cured in an autoclave in step 3. The curing conditions are usually pressure 10~20Kg/d, temperature 160~1
The temperature is 80°C and the time is 5 to 10 hours.

Due to the above autoclave curing, the calcium silicate reaction between the cement and the silicic acid-containing substance is completely carried out, and when expandable thermoplastic beads are added to the core layer, the expandable thermoplastic beads are completely foamed. At the same time, the plastic foam particles formed by the foaming of the expandable plastic beads melt, and the foaming agent in the cells escapes to the outside world, and the plastic foam rapidly contracts, creating a large number of pores inside the core layer. is formed. A plastic coating layer resulting from the thermoplastic foam particles is formed on the inner wall surface of the hole.

In this way, the inorganic molded plate of the present invention having embossing on both sides or one side is manufactured, and the thickness of the front and back layers of the inorganic molded plate of the present invention is usually 10 to 30% of the total thickness.

[Action/Effect]

In the present invention, since the density of the front and back layers is 1.0 to 1.2, the front and back surfaces are dense, and the density of the core layer is 0.8 to 1.
．． Since it is 0, the core layer has appropriate cushioning properties. Therefore, when embossing is applied from the front and/or back surfaces, the core layer is easily deformed by the pressing force applied through the front and back layers. In this way, the embossing on the front and/or back side of the inorganic molded plate becomes extremely clear, and deep embossing can also be done easily.
come. Since the density of the front and back layers is equal to that between the grooves, the inorganic molded plate of the present invention is unlikely to warp to either side5, and has extremely good shape stability and dimensional stability.

〔Example〕

Example 1 (1) The formulation of mixture A is as follows.

Portland cement 47% by weight silica sand
3゜Pearlite 10 〃 Flake Medium L 5 N Wood Flour Medium 25 Aluminum Sulfate 3 Umbrella 1: As a flake, average mesh size is 4.5, average thickness is 0
．． 6- is used.

The wood flour used has an average particle size of 20 mesh.

(2) The formulation of mixture B is as follows.

Portland cement 46% by weight silica sand
28 Perlite 10 Wood fiber bundle 10 Expandable polystyrene beads 3 (pre-foamed product) Aluminum sulfate 3 Wood fiber bundles have an average diameter of 1.0 m and a length of 20 branches and/or curves and/or folds. Use what you are made to do.

(3) A method for producing an inorganic molded plate using the mixtures A and B is shown in FIGS. 1 to 3. In the forming apparatus shown in FIG. 1, (1) is a forming chamber; ), a lower mold plate (3) having an uneven pattern (3) A on its surface is arranged on the conveyor belt conveyor (2), and the lower mold plate (3) is moved by the conveyor belt (2) in the direction of the arrow. It is transported in the direction A. A supply belt conveyor (4) is disposed above the lower template (3), and at the end of the supply belt conveyor (4) a supply brush (5) is disposed on the upper side and a cleaning brush (6) is disposed on the lower side. are used to constitute the dispersion device. A blower (72) housed in a casing (71) is provided on the lower mold plate (3) of the forming chamber (1) in the conveying direction (later side), and a distribution duct (74) is connected to the blower (72). A main blower device (7) consisting of a pair of upper and lower air outlets (73) and (73) communicating through the forming chamber (1) is disposed, and the air outlet (73) is connected to the lower mold plate (3) II in the forming chamber (1). Air is blown in the direction opposite to the blowing direction (front side), and a blower is installed on the front side of the forming chamber (1) to recover the air blown from the air outlet (73). (7
2) is opened. Further, at the lower part of the front stage side of the forming chamber (1), there is a duct (72) branched from the distribution duct (74) to the blower (72).
A sub-air blower (7)A is arranged, which is composed of an air outlet (73)A communicating through 74)A, and the air outlet (73)A blows wind toward the rear stage side. In addition, the main ventilation system W
The air outlet (73) of (7) and the sub-air blower f [(7) A have a handle (75), (75) A
Air volume control valve (76), (76) operated by
A is attached. Further, in the forming chamber (1), a sieve frame (9) is installed opposite to the air outlet (73) so that the angle of inclination can be adjusted and the sieve frame (9) can be moved back and forth. A dispersion device similar to the forming device is disposed downstream of the forming device, and includes a supply belt conveyor (4), a supply brush (5), and a cleaning brush (6).
Furthermore, a forming device whose front and rear directions are reversed from that of the forming device described above is arranged at a subsequent stage.

In the former forming device, the mixture A
A mixture (10) containing 40% by weight of water is conveyed on a supply belt conveyor (4) in the direction of the arrow, and at the end of the supply belt conveyor (4), it is conveyed by a spreading roll (5) rotating in the convex direction of the arrow. Loosen the mixture (1o)\
Drop it from the rear stage of the forming chamber (1). The mixture (
10) is first oriented in the front stage direction as shown by arrow E by the wind blown in the front stage direction shown by arrow 2 from the air outlet (73) of the main air blower (7), and then sieved by the sieve frame (9). After that, the finer powder in the mixture (10) is further air-selected by the air blown from the air outlet (73) and placed on the lower mold plate (3) at the earlier stage in the forming chamber (1). Coarse powder falls and accumulates on the lower mold plate (3) at a later stage in the forming chamber (1), but at this time, finer powder falls and accumulates on the lower mold plate (3) directly above the lower mold plate (3). The wind blown from the air outlet (73)A of the sub-air blower (7)A in the backward direction shown by the arrow G causes the air to be oriented slightly in the backward direction as shown by the arrow H. The coarsest powder remains on the sieve frame (9) and falls from the top of the sieve frame (9) as shown by the arrow to the forming chamber (1).
) is deposited on the lower mold plate (3) at the last stage. The lower mold plate (3) is connected to the conveyor belt conveyor (2) as described above.
) in the forming chamber (1) from the front stage side to the rear stage side, the finest powder is deposited at the bottom on the lower mold plate (3), and the particle size becomes coarser as it goes up. Powder will be deposited. In this way, as shown in FIG. 3, a surface mat (10) A having a structure in which the grain size becomes finer toward the bottom is formed. The thickness of the surface mat (10) A is 8 m.

In the surface mat (10)^, as described above, the fine powder is slightly moved toward the rear by the wind blown from the air outlet (73)A of the sub-air blower (7)A right above the lower mold plate (3). Since the powder is oriented, the fine powder is also filled in the front side of the protrusions (31)A of the uneven pattern (3)A of the lower mold plate (3), as shown in FIG.

In this way, the surface mat (10) A is produced,
Furthermore, the surface mat (
to) Sprinkle a mixture of the above mixture B and 40% by weight of water on A to form a core layer mat (20) as shown in Figure 4.
Form A. The thickness of the core layer mat (20) A is 50 na. Further, the mixture (10) is similarly spread using a subsequent forming device to form a back layer mat (30) A as shown in FIG. The thickness of the backing mat (30) A is 8 m+. As mentioned above, the forming device at the rear stage is arranged in the opposite direction from the forming device at the front stage, so the back layer mat (
30) A has a structure in which the coarsest powder is deposited at the bottom, and the particle size becomes finer as it goes up, contrary to the surface mat (10) A.

In this way, the surface layer mat (10) A, the core layer mat (2)
0) A, back layer mat (30) A is formed, but as shown in FIG. After contacting and press forming, the pressure is 10 kg/al! , temperature 70℃
Press hardening was performed for 25 hours at The obtained laminate molded body is a plate-shaped body with a thickness of 18 m, and the laminate molded body is then placed in an autoclave under a pressure of 15 kg/co! , temperature 165℃
The cement and silica sand in the laminate were cured for 7 hours by a calcium silicate reaction, and the expandable polystyrene beads in the core layer were foamed and then softened and shrunk.

The inorganic molded plate thus obtained has a density of 1.10 for the front and back layers, a density of 0.85 for the core layer, a dense and smooth surface with a clear uneven pattern, and is lightweight. It has excellent sound and heat insulation properties.

Example 2 (1) The formulation of mixture A is as follows.

Cement ratio 1 50% by weight Silica hume 30 Perlite 10 Wood powder umbrella 2 10 *1: As the cement, a mixture of Bortland cement and alumina cement in a weight ratio of 8:2 is used.

8: The same wood flour as that used in Example 1 is used.

(2) The formulation of mixture B is as follows.

Cement *1 50% by weight silica hume 27 # Perlite 10 〃 Wood fiber bundle *'' 10 Polystyrene foam granules 3 〃 -1 = Cement with the same formulation as that used in mixture A is used.

$2: The same wood fiber bundle as used in Example 1 is used.

(3) An inorganic molded plate is manufactured by the dry manufacturing method in the same manner as in Example 1. At this time, the polystyrene foam particles soften and shrink during autoclave curing.

The inorganic molded plate thus obtained has a density of 1.05 for the front and back layers, a density of 0.80 for the core layer, a dense and smooth surface with a clear uneven pattern, and is lightweight. It has excellent sound and heat insulation properties.

Example 3 (1) The formulation of mixture A is as follows.

Portland cement 47% by weight Shirasu balloon 10 Silica sand 30 Flake*15 Wood flour-25 Sodium aluminate 3 *1: The same flakes as those used in Example 1 are used.

Fist 2 The same wood powder as used in Example 1 is used.

(2) The formulation of mixture B is as follows.

Portland cement 46% by weight Shirasu balloon 10 Silica sand 28 Wood fiber bundle skewers 10 Expandable polystyrene beads 3 (pre-foamed product) Sodium aluminate 3 I: The same wood fiber bundles as those used in Example 1 are used.

(3) An inorganic molded plate is manufactured by the dry manufacturing method in the same manner as in Example 1.

The inorganic molded plate thus obtained has a density of 1.15 for the front and back layers and a density of 0.90 for the core layer, and has a dense, smooth, lightweight, and clear uneven pattern on the surface. It has excellent sound and heat insulation properties.

[Brief explanation of drawings]

1 to 6 show Example 1 of the present invention,
FIG. 1 is a side view of the device, FIG. 2 is a plan view of the device, and FIG. 3 is an explanatory diagram of the state of the formed surface mat.
Figure 4 is an explanatory diagram of the state of the formed surface layer and core layer mat, Figure 5 is an explanatory diagram of the state of the formed surface layer, core layer, and back layer mat, and Figure 6 is an explanatory diagram of the state of the formed surface layer, core layer, and back layer mat. It is an explanatory view of a state where a template is placed. In the figure, (3), (11)...template, (3)A, (
11) A... uneven pattern, (10) A... surface layer mat, (20) A... core layer mat. (30) A... Back layer mat

Claims (1)

[Claims] It consists of a front and back layer and a core layer, and the density of the front and back layers is 1.0 to 1.
．． 2, the density of the core layer is 0.8 to 1.0,
An inorganic molded plate characterized by having an embossed surface and/or back surface.